Semiconductor chips are manufactured in such a manner that after a plurality of integrated circuits have been formed in a batch mode under semiconductor wafer condition, the semiconductor wafer is cut along scribe lines so as to be divided with respect to each of the integrated circuits. While several wafer cutting methods have been conventionally employed, for instance, such a wafer cutting method is known that the wafer is mechanically cut by rotary blades (refer to, for example, patent publication 1); and instead of the mechanical cutting method, another wafer cutting method is known as a method based upon a plasma dicing process in which portions of the wafer which correspond to scribe lines are removed by a plasma etching process so as to divide the wafer (refer to, for example, patent publication 2), and the like.
On the other hand, in stages for manufacturing semiconductor chips, when circuit patterns are formed, test patterns employed in characteristic tests are formed on regions corresponding to the scribe lines; and after functions of these test patterns have been accomplished, these test patterns are cut off, or removed during dicing process. In the example shown in the patent publication 1, prior to the dicing process for cutting the wafer itself, the test patterns have been previously removed by employing the rotary blade having the wider width. As a result, since the entire portion of the test patterns are removed, it is possible to avoid “burrs” of cut planes, which occur when the test patterns are partially cut.
Then, another method indicated in a patent publication 3 has been proposed as to removing of the test patterns in such a case that the plasma dicing process is applied. That is, in this example, a protection seat is adhered to a circuit forming plane of a semiconductor wafer in such a manner that the protection seat is contacted to test patterns; subsequently, a plasma etching-purpose mask is formed on a rear plane of the circuit forming plane, and the wafer is cut by a plasma etching process; and then, such a test pattern which has not been removed in the plasma etching process but has been left is released in combination with the protection seat, and thus, is removed. As a consequence, after the plasma etching process, the side of the circuit forming plane is no longer plasma-ashed in order to remove the mask, and therefore, damages of the circuit forming plane caused by the plasma ashing process can be eliminated.
Patent Citation 1: JP-A-2001-250800
Patent Citation 2: JP-A-2005-191039
Patent Citation 3: JP-A-2006-179768